直驱式电液伺服系统低速控制研究

发布时间：2019-01-20 09:58

【摘要】：直驱式电液伺服系统是一种新型的电液伺服系统。在新型的直驱式电液伺服系统中,电机即作为系统的能量元件驱动双向定量泵转动带动负载运动,又作为系统的控制元件通过控制电机的转速和旋转方向来控制双向定量泵的转速和旋转方向来控制系统液压油的流速和循环方向,进而控制负载运动。该种系统具有体积小、耗能低、噪声低、效率高、控制灵活等诸多优点在航空、航天、航海领域有着广泛的应用空间。随着系统的不断应用,如何提高系统低速运动的性能已经成为了电液伺服系统的研究的一个重要方向。在新型的直驱式电液伺服系统中,研究系统低速特性因素对系统的影响及针对各种影响因素所应实施的补偿方法就变得尤为重要。在本文中,建立了交流异步电机运动方程,直取式电液伺服系统液压动力机构运动方程,分别得到了交流异步电机与液压动力机构的传递函数,并求得了直驱式电液伺服系统的传递函数。基于Simulink软件平台建立了直接转矩控制异步电机仿真模型。同时,也建立了基于AMEsim软件平台的液压动力机构仿真模型,并通过两部分的合并,建立了直驱式电液伺服系统联合仿真模型。进行了理想状态下直驱式电液伺服系统的典型输入仿真,得到了理想状态下系统对典型输入的响应曲线,验证了系统的稳定性。在本文中,分析了摩擦干扰力矩、齿轮泵容积损耗、齿轮泵机械损耗以及电机低速旋转状态下的转矩脉动等等各种影响系统低速性能的因素,分别建立了数学模型。选择LuGre摩擦模型建立摩擦干扰力矩的仿真模型、建立了以齿轮泵端面间隙泄露与齿轮泵径向间隙泄露为主的齿轮泵容积损耗仿真模型、建立了以齿轮泵齿顶端面与液体的粘性摩擦损失为主的齿轮泵机械损耗仿真模型。分别就各个因素注入到直驱式电液伺服系统理想状态下仿真模型中进行对比仿真,观察并分析了各因素对直驱式电液伺服系统的影响。在本文中,通过分析各因素对直驱式电液伺服系统的影响,选择了高增益PID控制器与反步积分自适应控制器分别对摩擦力矩进行了补偿。建立了高增益PID控制器与反步积分自适应控制器的数学模型,并在上述模型的基础上分别建立了高增益PID控制器与反步积分自适应控制器的仿真模型,将其分别注入到含摩擦干扰力矩的直驱式电液伺服系统仿真模型中,建立经过补偿的含摩擦干扰力矩的直驱式电液伺服系统仿真模型。通过高增益PID控制器补偿和反步积分自适应控制器补偿两种方法的对比仿真,验证了反步积分自适应控制器对摩擦干扰力矩的补偿效果更加有效,补偿效果符合要求。针对齿轮泵容积损耗问题,针对齿轮泵容积损耗的特点设计了物理补油装置,并针对补油装置和液压锁阀设计了集成阀块。完成了直驱式电液伺服系统低速控制的研究内容。
[Abstract]:Direct drive electro-hydraulic servo system is a new type of electro-hydraulic servo system. In a new type of direct-drive electro-hydraulic servo system, the motor is used as the energy element of the system to drive the bidirectional quantitative pump rotation and drive the load movement. As the control element of the system, the speed and direction of rotation of the bidirectional quantitative pump are controlled by controlling the speed and the direction of rotation of the motor to control the velocity and circulation direction of the hydraulic oil of the system, and then to control the movement of the load. The system has many advantages, such as small volume, low energy consumption, low noise, high efficiency, flexible control and so on. With the continuous application of the system, how to improve the performance of the system at low speed has become an important research direction of the electro-hydraulic servo system. In a new type of direct-drive electro-hydraulic servo system, it is very important to study the influence of the low speed characteristic factors on the system and the compensation method for various factors. In this paper, the equation of motion of AC asynchronous motor and the equation of motion of hydraulic power mechanism of direct electro-hydraulic servo system are established, and the transfer functions of AC asynchronous motor and hydraulic power mechanism are obtained respectively. The transfer function of direct-drive electro-hydraulic servo system is obtained. The simulation model of direct torque control asynchronous motor is established based on Simulink software platform. At the same time, the simulation model of hydraulic power mechanism based on AMEsim software platform is established, and the joint simulation model of direct-drive electro-hydraulic servo system is established by combining the two parts. The typical input simulation of direct-drive electro-hydraulic servo system in ideal state is carried out. The response curve of the system to typical input in ideal state is obtained and the stability of the system is verified. In this paper, the factors that affect the low speed performance of the system, such as friction disturbance moment, gear pump volume loss, gear pump mechanical loss and torque ripple under the condition of motor low speed rotation, are analyzed, and the mathematical models are established respectively. The LuGre friction model is selected to establish the simulation model of friction disturbance moment, and the simulation model of gear pump volume loss is established, which is mainly based on the leakage of the end clearance of gear pump and the leakage of radial clearance of gear pump. The mechanical loss simulation model of gear pump is established, which is based on the viscous friction loss between the top surface of gear pump tooth and liquid. Each factor is injected into the ideal simulation model of direct-drive electro-hydraulic servo system, and the influence of each factor on direct-drive electro-hydraulic servo system is observed and analyzed. In this paper, by analyzing the influence of various factors on the direct-drive electro-hydraulic servo system, the high gain PID controller and the backstepping integral adaptive controller are selected to compensate the friction torque respectively. The mathematical models of high gain PID controller and backstepping integral adaptive controller are established, and the simulation models of high gain PID controller and backstepping integral adaptive controller are established based on the above models. It is injected into the simulation model of direct-drive electro-hydraulic servo system with friction disturbance torque, and the simulation model of direct-drive electro-hydraulic servo system with friction disturbance moment is established. Through the comparison and simulation of high gain PID controller compensation and backstepping integral adaptive controller compensation, it is proved that the backstepping integral adaptive controller is more effective to compensate friction disturbance torque, and the compensation effect meets the requirements. Aiming at the problem of gear pump volume loss, the physical oil filling device is designed according to the characteristics of gear pump volume loss, and the integrated valve block is designed for oil filling device and hydraulic lock valve. The research content of low speed control of direct drive electro-hydraulic servo system is completed.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM921.541

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